{"id":"CVE-2026-116886","kind":"vulnerability","aliases":["CVE-2026-116886"],"related":[],"title":"Semantic MediaWiki: stored XSS via External identifier values runs scripts","description":"Semantic MediaWiki from 2.5.0 before 7.3.1 contains a stored cross-site scripting vulnerability that allows users with page-edit rights to inject scripts via External identifier property values. Attackers can annotate markup payloads that ExternalIdentifierValue renders unescaped on Special:Browse, executing JavaScript in viewers' sessions, including administrators.","summary":"Semantic MediaWiki versions from 2.5.0 before 7.3.1 render External identifier property values unescaped on Special:Browse. A user with page-edit rights can store a script payload that runs in the browser of anyone who views the page, including administrators.","severity":"medium","cvss":5.4,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["mediawiki","package","self-hosted","semantic-mediawiki"],"not_affected_if":["already-on-7.3.1-or-later","no-external-identifier-properties"],"how_to_check":"- Check the installed Semantic MediaWiki version in Special:Version or the `composer.lock` / `extensions/SemanticMediaWiki` directory.\n- Check whether any pages use the External identifier property type.","fix":"- Upgrade Semantic MediaWiki to `7.3.1` or later.","status":"open","published_at":"2026-10-27T11:17:30+00:00","first_seen_at":"2026-10-27T11:31:27+00:00","triaged_at":"2026-10-27T11:32:11+00:00","updated_at":"2026-10-27T11:32:11+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-27T11:32:11Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade Semantic MediaWiki to `7.3.1` or later.","reach":"internet","title":"Semantic MediaWiki: stored XSS via External identifier values runs scripts","impact":"medium","summary":"Semantic MediaWiki versions from 2.5.0 before 7.3.1 render External identifier property values unescaped on Special:Browse. A user with page-edit rights can store a script payload that runs in the browser of anyone who views the page, including administrators.","category":"package","nicknames":[],"who_cares":["mediawiki","semantic-mediawiki","self-hosted"],"confidence":0.7,"needs_auth":"yes","worst_case":"Scripts run in admin sessions, enabling account takeover on the wiki","analyst_note":"","how_to_check":"- Check the installed Semantic MediaWiki version in Special:Version or the `composer.lock` / `extensions/SemanticMediaWiki` directory.\n- Check whether any pages use the External identifier property type.","needs_analyst":false,"not_affected_if":["already-on-7.3.1-or-later","no-external-identifier-properties"],"who_is_affected":"Wikis running Semantic MediaWiki from 2.5.0 up to but not including 7.3.1 are exposed. The attacker needs page-edit rights, so wikis that restrict editing to trusted users have less exposure, but any editor's stored script runs for every viewer, including administrators.","user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000603,"input_tokens":3356,"output_tokens":534,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-116886':13A,16A '-2026':12A,15A '2.5.0':29B,69C '7.3.1':31B,71C 'administr':65B,114C 'allow':81C 'annot':98C 'anyon':59B 'attack':96C 'brows':40B,107C 'browser':57B 'contain':72C 'cross':76C 'cross-sit':75C 'cve':11A,14A 'edit':46B,86C 'execut':108C 'extern':6A,33B,92C 'externalidentifiervalu':102C 'host':21B 'identifi':7A,34B,93C 'includ':64B,113C 'inject':89C 'javascript':109C 'markup':99C 'mediawiki':2A,17B,24B,26B,67C 'packag':18B 'page':45B,63B,85C 'page-edit':44B,84C 'payload':52B,100C 'properti':35B,94C 'render':32B,103C 'right':47B,87C 'run':9A,54B 'script':10A,51B,78C,90C 'self':20B 'self-host':19B 'semant':1A,23B,25B,66C 'semantic-mediawiki':22B 'session':112C 'site':77C 'special':39B,106C 'store':3A,49B,74C 'unescap':37B,104C 'user':42B,82C 'valu':8A,36B,95C 'version':27B 'via':5A,91C 'view':61B 'viewer':111C 'vulner':79C 'xss':4A","nicknames":[],"mitigations":[],"who_affected":"Wikis running Semantic MediaWiki from 2.5.0 up to but not including 7.3.1 are exposed. The attacker needs page-edit rights, so wikis that restrict editing to trusted users have less exposure, but any editor's stored script runs for every viewer, including administrators.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T11:17:30+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-116886","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-116886","severity":null,"published_at":"2026-10-27T11:17:30+00:00","modified_at":"2026-10-27T11:17:30+00:00","first_seen_at":"2026-10-27T11:31:27+00:00","fetched_at":"2026-10-27T11:31:27+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}